Directions

In a large nonstick skillet, heat 1 tablespoon oil over medium-high. Add onions and season with salt and pepper. Cook, stirring often, until softened and just beginning to brown, 10 minutes. Reduce heat to medium; cook, stirring occasionally, until onions are deep golden brown and very soft, 30 minutes. (Refrigerate in an airtight container, up to 1 day. Bring to room temperature before using.)

Meanwhile, in a large pot of boiling salted water, cook green beans until crisp-tender and bright green, about 6 minutes. Drain and toss with tarragon and 1 teaspoon oil; season with salt and pepper. Transfer beans to a platter and top with onions.

Cook's Notes

Cooking onions until they are golden brown, or caramelized, both deepens and amplifies their flavor. They're delicious on green beans, but also on pizza, baked potatoes, or grilled cheese sandwiches. You may want to make a double batch, in fact, since they're an easy way to dress up any meal.